diff mbox series

[v2,3/3] PCI: set dma-can-stall for HiSilicon chip

Message ID 1610960316-28935-4-git-send-email-zhangfei.gao@linaro.org
State New
Headers show
Series [v2,1/3] PCI: PASID can be enabled without TLP prefix | expand

Commit Message

Zhangfei Gao Jan. 18, 2021, 8:58 a.m. UTC
HiSilicon KunPeng920 and KunPeng930 have devices appear as PCI but are
actually on the AMBA bus. These fake PCI devices can support SVA via
SMMU stall feature, by setting dma-can-stall for ACPI platforms.

Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com>
---
Property dma-can-stall depends on patchset
https://lore.kernel.org/linux-iommu/20210108145217.2254447-1-jean-philippe@linaro.org/

 drivers/pci/quirks.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Comments

Bjorn Helgaas Jan. 21, 2021, 4:57 p.m. UTC | #1
On Mon, Jan 18, 2021 at 04:58:36PM +0800, Zhangfei Gao wrote:
> HiSilicon KunPeng920 and KunPeng930 have devices appear as PCI but are
> actually on the AMBA bus. These fake PCI devices can support SVA via
> SMMU stall feature, by setting dma-can-stall for ACPI platforms.
> 
> Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com>
> ---
> Property dma-can-stall depends on patchset
> https://lore.kernel.org/linux-iommu/20210108145217.2254447-1-jean-philippe@linaro.org/
> 
>  drivers/pci/quirks.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 873d27f..b866cdf 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -1827,10 +1827,23 @@ DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_HUAWEI, 0x1610, PCI_CLASS_BRIDGE_PCI
>  
>  static void quirk_huawei_pcie_sva(struct pci_dev *pdev)
>  {
> +	struct property_entry properties[] = {
> +		PROPERTY_ENTRY_BOOL("dma-can-stall"),
> +		{},
> +	};
> +
>  	if (pdev->revision != 0x21 && pdev->revision != 0x30)
>  		return;
>  
>  	pdev->pasid_no_tlp = 1;
> +
> +	/*
> +	 * Set the dma-can-stall property on ACPI platforms. Device tree
> +	 * can set it directly.
> +	 */
> +	if (!pdev->dev.of_node &&
> +	    device_add_properties(&pdev->dev, properties))
> +		pci_warn(pdev, "could not add stall property");

What's the purpose of adding the "dma-can-stall" property?  I don't
see any reference to that property in the tree or in this series.  If
this is related to some other series that uses it, perhaps this part
should be moved to that series?

>  }
>  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_HUAWEI, 0xa250, quirk_huawei_pcie_sva);
>  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_HUAWEI, 0xa251, quirk_huawei_pcie_sva);
> -- 
> 2.7.4
>
Bjorn Helgaas Jan. 21, 2021, 5:50 p.m. UTC | #2
On Thu, Jan 21, 2021 at 10:57:09AM -0600, Bjorn Helgaas wrote:
> On Mon, Jan 18, 2021 at 04:58:36PM +0800, Zhangfei Gao wrote:
> > HiSilicon KunPeng920 and KunPeng930 have devices appear as PCI but are
> > actually on the AMBA bus. These fake PCI devices can support SVA via
> > SMMU stall feature, by setting dma-can-stall for ACPI platforms.
> > 
> > Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
> > Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> > Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com>
> > ---
> > Property dma-can-stall depends on patchset
> > https://lore.kernel.org/linux-iommu/20210108145217.2254447-1-jean-philippe@linaro.org/
> > 
> >  drivers/pci/quirks.c | 13 +++++++++++++
> >  1 file changed, 13 insertions(+)
> > 
> > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> > index 873d27f..b866cdf 100644
> > --- a/drivers/pci/quirks.c
> > +++ b/drivers/pci/quirks.c
> > @@ -1827,10 +1827,23 @@ DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_HUAWEI, 0x1610, PCI_CLASS_BRIDGE_PCI
> >  
> >  static void quirk_huawei_pcie_sva(struct pci_dev *pdev)
> >  {
> > +	struct property_entry properties[] = {
> > +		PROPERTY_ENTRY_BOOL("dma-can-stall"),
> > +		{},
> > +	};
> > +
> >  	if (pdev->revision != 0x21 && pdev->revision != 0x30)
> >  		return;
> >  
> >  	pdev->pasid_no_tlp = 1;
> > +
> > +	/*
> > +	 * Set the dma-can-stall property on ACPI platforms. Device tree
> > +	 * can set it directly.
> > +	 */
> > +	if (!pdev->dev.of_node &&
> > +	    device_add_properties(&pdev->dev, properties))
> > +		pci_warn(pdev, "could not add stall property");
> 
> What's the purpose of adding the "dma-can-stall" property?  I don't
> see any reference to that property in the tree or in this series.  If
> this is related to some other series that uses it, perhaps this part
> should be moved to that series?

Sorry, I missed your note about this above!  Thanks for the pointer.

I hate having code in the tree that's useless pending some other
series, but I guess doing it this way helps avoid ordering issues
between this series and that one.

But please include the lore URL to Jean-Philippe's series in the
commit log so that if this patch is merged before Jean-Philippe's,
people at least have a hint about what's going on.

> >  }
> >  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_HUAWEI, 0xa250, quirk_huawei_pcie_sva);
> >  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_HUAWEI, 0xa251, quirk_huawei_pcie_sva);
> > -- 
> > 2.7.4
> >
diff mbox series

Patch

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 873d27f..b866cdf 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -1827,10 +1827,23 @@  DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_HUAWEI, 0x1610, PCI_CLASS_BRIDGE_PCI
 
 static void quirk_huawei_pcie_sva(struct pci_dev *pdev)
 {
+	struct property_entry properties[] = {
+		PROPERTY_ENTRY_BOOL("dma-can-stall"),
+		{},
+	};
+
 	if (pdev->revision != 0x21 && pdev->revision != 0x30)
 		return;
 
 	pdev->pasid_no_tlp = 1;
+
+	/*
+	 * Set the dma-can-stall property on ACPI platforms. Device tree
+	 * can set it directly.
+	 */
+	if (!pdev->dev.of_node &&
+	    device_add_properties(&pdev->dev, properties))
+		pci_warn(pdev, "could not add stall property");
 }
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_HUAWEI, 0xa250, quirk_huawei_pcie_sva);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_HUAWEI, 0xa251, quirk_huawei_pcie_sva);